UTP Network Cable Info

Specifications for Cat3, Cat4, Cat5, Cat5e, Cat6, and Cat7 Cables

Category	Type	Spectral B/W	Length	LAN Applications	Notes
Cat3	UTP	16 MHz	100m	10Base-T, 4Mbps	Now mainly for telephone cables
Cat4	UTP	20 MHz	100m	16Mbps	Rarely seen
Cat5	UTP	100MHz	100m	100Base-Tx,ATM,CDDI	Common for current LANs
Cat5e	UTP	100MHz	100m	1000Base-T	Common for current LANs
Cat6	UTP	250MHz	100m		Emerging
Cat7	ScTP	600MHz	100m

CAT5, CAT5e, and CAT6 UTP Solid Cable Specifications Comparison
	Category 5	Category 5e	Category 6
Frequency	100 MHz	100 MHz	250 MHz
Attenuation (Min. at 100 MHz)	22 dB	22 dB	19.8 dB
Characteristic Impedance	100 ohms ± 15%	100 ohms ± 15%	100 ohms ± 15%
NEXT (Min. at 100 MHz)	32.3 dB	35.3 dB	44.3 dB
PS-NEXT (Min. at 100 MHz)	no specification	32.3 dB	42.3 dB
ELFEXT (Min. at 100 MHz)	no specification	23.8 dB	27.8 dB
PS-ELFEXT (Min. at 100 MHz)	no specification	20.8 dB	24.8 dB
Return Loss (Min. at 100 MHz)	16.0 dB	20.1 dB	20.1 dB
Delay Skew (Max. per 100 m)	no specification	45 ns	45 ns

credit to http://discountcablesusa.com/ethernet-cables100.html